What is the new normal Body temperature?
A new study of temperature patterns shows that the average human body temperature fell as a result of physiological changes since the 19th century. The new study authors also illustrate possible causes of those changes.
Most of us only take our temperatures when we are worried that we have a fever, as a result of an infection or a cold, for example.
But body temperature can indicate and be influenced by many other factors; lifestyle habits, age, and ambient temperature can all influence how our body disperses heat.
Body temperature is also a sign of metabolic health. Specifically, the authors of the new study explain that human body temperature indicates metabolic rate, some of which have been associated with longevity and body size.
So what is our normal body temperature? In 1851, a German physician called Carl Reinhold August Wunderlich surveyed 25,000 people in one city and established that 37°C is the standard temperature of the human body.
However, recent analyses and surveys suggest that the average body temperature is now lower.
For instance, a study of more than 35,000 people in the United Kingdom and nearly 250,000 temperature measurements found that 36.6°C is the average oral temperature. Could this discrepancy be a result of changes in measurement tools? Or, do the new findings reflect higher life expectancy and better overall health?
Myroslava Protsiv, then at Stanford University’s Division of Infectious Diseases and Geographic Medicine, in California, and colleagues set out to investigate.
The team hypothesized that “the differences observed in temperature between the 19th century and today are real and that the change over time provides important physiologic clues to alterations in human health and longevity since the Industrial Revolution.”